Her body is so perfectly preserved that it is hard to believe this girl died more than 500 years ago.

But what is even more remarkable is that scientists today have been able to learn the secrets of her death – by analysing her hair.

The 13-year-old Incan girl was heavily dosed with alcohol and coca leaves, which form the basis of cocaine, before being left to die of exposure high in the Andes as a sacrifice.

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The children included a 13-year-old known as the 'Llullaillaco Maiden' whose remains were struck by lightning and charred. She was well fed and chosen for her beauty and possibly nobility

Axial radiograph of the interior of the mouth, showing the coca (green) held between the teeth. Coca and alcohol were substances that induced altered states interpreted as sacred and which could suggest to victims and those associated with them the proximity of the divine beings

Ritual killings were common within the Incan culture. In 1999 three Children of Llullaillaco, who found deep frozen were found with an extraordinary collection of elaborate gold, silver and shell statues, textiles and pots containing food The children included a 13-year-old known as the 'Llullaillaco Maiden'

Child sacrifice was called capacocha. The process of capacocha could begin years before the selected person was killed. A mummified body of a child who was killed during one such sacrifice is pictured here

The older girl's face - which showed red ochre markings - was creased from the place it rested on her shawl

The chicha, an alcoholic drink made from fermented maize, would have
helped her deal with the cold.

But it could also have hastened her
death by stopping her from shivering.

There is no evidence that the girl, known as the Llullaillaco Maiden
after the mountain in northwest Argentina, was brutally killed.

Instead, it is thought she died of exposure. Priests would have waited
for her to fall unconscious before placing her in a burial chamber.

Dr Andrew Wilson, from the University of Bradford, said: ‘We think it
likely that the Maiden was selected for sacrifice 12 months before her
death, after which her treatment changed, corresponding to the sharp
rise in coca consumption.

‘She was then probably involved in a series of rituals, involving
consumption of coca and alcohol in the build up to her sacrifice.

‘Both substances were controlled, were considered elite products.

‘The fact that in her final weeks the maiden shows consistently higher
levels of coca and alcohol use compared to the younger children suggests
there was a greater need to sedate her in the final weeks of life.’